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HELP SUBSCRS                                        Steven Hardy, October 1977

    subscrs(integer, string) -> character-code;
    character-code -> subscrs(integer, string);

This procedure is used to access strings; if the value of the variable S is a
string then

    s(4) =>

is equivalent to

    subscrs(4, s)

though the latter will in general be faster.

For example:

    'abcd' -> s;
    s(4) =>
    ** 101

101 is the ASCII code for `d`. Character codes can also be found by using the
` symbol, for example:

    `a` =>
    ** 97

The components of a string can be updated, either by treating the string as a
procedure, or by using the updater of SUBSCRS, e.g.

    `e` -> s(1);
    `f` -> subscrs(2,s);
    s =>
    ** 'efcd'


For super-efficient programs there is a 'fast' version of SUBSCRS, which is
dangerous to use, because it does not check that it has been given the right
arguments.  See REF * FASTPROCS;